And I thought I was brave considering blue flaming wallpaper (in the end after having a similar problem I went with something else that was easier to get a good complimentary colour). I'm with Jules - if it's more neutral you're after I'd go for the ivory of th branchs

I would go with a pale grey/beige colour. Something like a Farrow and Ball Dimity or Clunch would look lovely. I think you'll find it hard to match wallpaper so would stick with flat paint. I would then introduce a more definite accent colour and perhaps a new brighter rug. Oranges and mustard yellows would look nice with the sofa. Hope this helps

All doors and windows are upvc light oak, but it looks more like a mid/tan brown. I was thinking about a vintage grey/cream for the doors. Or just stick to all white?

For a bright modern kitchen I think a wooden floor, or wood effect porcelain, will go beautifully. Porcelain is quite cold underfoot so you may consider under floor heating. Worktop I would keep it simple with maybe a white quartz with some veining. You could continue the worktop up as a splashback with an upstand all round. This will give a clean look, but if you want tiles then don’t need an upstand. There are so many gorgeous tiles about so it’s worth having a search online. Here’s some ideas.